Study the effect of fortifying with selenium or physiochemical and sensory properties of the functional yogurt process.

Abstract

The present study aimed to determine the effect of selenium on the physicochemical and sensory properties  of the functional yogurt process by fortifying  the full fat milk with four concentrations of organic  selenium 50,100,150 and 200mg/L  presented by T1,T2,T3,and T4 respectively, as well as the control treatment in which the yogurt  was made from full fat milk without added selenium . chemical tests were conducted  to determine the percentage of moisture , protein ,fat, carbohydrate, ash ,non-protein nitrogen, degree of fat acidity, peroxide number and physical tests which included total acidity, pH value, viscosity, whey exaggerated and water retention  as well as sensory, evaluation immediately after manufacture and storage at a temperature of (5 ± 1)C^º for 21days. The results showed that yogurt fortify with selenium were kept the moisture  control close to the moisture content of the control treatment, while during storage we observed a slight decrease in their values for all treatments. the percentage of fat was equal in all fortify and non-fortify  yogurt, and its percentage was increased in all treatments during storage. the percentage of protein and carbohydrate was close at yogurt for all treatments, and the percentages of non-protein  nitrogen and pH values were close for all treatments under study. Yogurt fortified with selenium were characterized by low degree of acid fat value and peroxide number immediately after manufacture as well as in all storage periods compared with high  values for the control treatments. fortifying with selenium led to improve the yogurt rheological properties represent by viscosity, whey exaggerated and water retention, in addition, fortifying with selenium improved the sensory properties of yogurts especially yogurt treatments fortified at a concentration of 100and 200 μm/L.